Electrical devices such as motors, generators, alternators, and the like, including automobile starters, alternators and generators, generally have a housing and an armature which rotates within the housing on a shaft. A stationary set of wire windings is fixed inside the housing, and another set of windings is wrapped around the armature shaft.
A ring commonly known as a commutator fits over the armature shaft adjacent the armature windings. The ends of the windings are soldered to a series of electrical contacts attached to the periphery of the commutator. Electrical current is transmitted to and from the armature windings through brushes attached to the housing which rub across the contacts of the commutator as the armature turns, making an electrical connection with the commutator.
The high cost of new replacement parts for automobiles and the like has created a demand for rebuilt motors, alternators and generators. Generally, when a unit is rebuilt, it is repaired, cleaned and reconditioned. Worn parts are often replaced, even, if they have not yet failed. The commutator contacts are made of metal, and over a period of time become corroded and worn as a result of exposure to the elements and the rubbing of the brushes. Thus, when a unit is rebuilt, the contacts of the commutator are generally resurfaced or replaced.
In the past, most commutator contacts were made of a substantial amount of metal, such as copper. When the unit was rebuilt, the contacts were generally resurfaced, without having to remove the commutator from the armature. However, because of increases in the price of metals such as copper, the use of commutators having metal contacts which are too thin to resurface has become more popular. To rebuild these units, a new commutator must be installed on the armature. If the worn commutator cannot be removed from the armature quickly and easily, the entire armature must be discarded and replaced.
Removal of the commutator is complicated by the fact that each of the contacts is individually soldered to the wires. Unsoldering the connections one at a time with a soldering iron is both tedious and time-consuming, and therefore expensive. Also, when the contacts are unsoldered by hand, the wires are generally moved out of the way as they are unsoldered, and are thereby distorted. When a new commutator is installed, each wire must be reformed. Thus, there is a need for apparatus which will remove a commutator from an armature quickly and easily, without unsoldering each wire connection individually. There is also a need for a commutator puller which does not grievously distort the wires when the commutator is removed.
Thus, an object of the present invention is to provide new and improved apparatus for rebuilding an electric motor, alternator, generator and the like. Another object is to provide new and improved apparatus for removing the commutator from the armature of an electric motor, alternator, generator and the like.
Still another object is to provide new and improved apparatus for removing a commutator from an armature with speed and ease, without unsoldering each wire connection individually, or grievously distorting the wires. Yet another object is to provide new and improved apparatus for removing a commutator from an armature by heating the solder on all of the commutator contacts simultaneously in a solder bath or the like, and removing the commutator before the molten solder hardens.
In keeping with one aspect of this invention, all of the contacts of an armature commutator are dipped in a hot solder bath, melting the solder on all of the wire connections simultaneously. When the solder melts, the commutator is immediately placed in a commutator puller. Power means push a plunger, which moves a spring-operated actuator, and forces a plurality of teeth against the commutator, holding it firmly in place. The plunger then pushes the armature shaft away from the commutator, disconnecting the commutator from the armature before the molten solder hardens. When the power means are disabled, the plunger returns to its original position, relaxing the spring. Tooth springs bring the teeth and actuator away from the commutator, releasing the commutator for removal from the commutator puller.